A typical dynamoelectric machine armature is assembled to an end cap or end frame at either end of the dynamoelectric machine. The end cap or end frame carries spring biased brushes that, in use, engage a commutator of the armature. One difficulty encountered in the assembly of the dynamoelectric machine is maintaining the brushes in a retracted position out of the way of the commutator of the armature as the armature shaft is inserted into a bearing in the end frame.
One known method for securing the brushes is illustrated in FIGS. 1 and 2. The brush holder body 16 holds the brush 14 and a biasing spring 12 during assembly using a finger 18, having an extension 22 and contact surface 20 contacting the brush 14. The contact surface 20 on extension 22 prevents spring 12 from forcing brush 14 out of the brush holder body 16 into the region where the commutator is to occupy.
During assembly, the motor commutator 26 comes in contact with the extension 22 of cantilever finger 18, pushing the finger 18 away from brush 14 so that contact surface 20 no longer retains brush 14 retracted. When this occurs, spring 12 is enabled to force brush 14 against commutator 26, which is the desired assembled position. During operation of the dynamoelectric machine, the fingers rub on the underside of the commutator 26 causing armature drag and the possibility of debris due to material wear and finger breakage. Additionally, noise may result from the finger 18 rubbing against the rotating commutator 26. The fingers 18 may be snapped or broken off as a result of this rubbing.